Samuel Ginn College of Engineeringhttp://hdl.handle.net/11200/5542018-08-12T18:03:04Z2018-08-12T18:03:04ZAU Smart Cart Senior Design Project Report Fall 2012http://hdl.handle.net/11200/490452017-10-26T01:19:57ZAU Smart Cart Senior Design Project Report Fall 2012
Team 3 consists of six members working together to design and build a fully autonomous shopping cart. The purpose of the cart is to perform as a personal shopping assistant to the user as he/she shops in different environments. The project must be able to meet the following requirements in order to be considered a success:
• Follow the user and maintain a safe distance
• Perform as a cart by carrying a fair amount of objects inside
• Respond to voice commands such as: stop and go
• Respond to hand gestures
As a result from a great deal of hard work put in by each member this semester the team has been successful in developing a working product. The AU SmartCart meets all the requirements set by the team and operates safely and accordingly to all available regulations.
In a day and age when humans are becoming increasingly lazy a robotic shopping cart is just the ticket for your everyday shopping desires. This product can be targeted to everyone from lazy young college students, which are too busy text messaging to merely push a cart, all the way up to older citizens that are unable to do so. For a successful company this project could prove to be a very good investment. The endless possibility of potential clientele would leave a company with a wide range of opportunities to cash in on its investment. Overall the AU SmartCart is a wonderful piece of equipment and should prove to be both useful and profitable for any company willing to invest.
A Solution of Rigid Perfectly Plastic Deep Spherical Indentation based on Slip Line Theoryhttp://hdl.handle.net/11200/485382015-11-16T14:42:18Z2015-11-16T00:00:00ZA Solution of Rigid Perfectly Plastic Deep Spherical Indentation based on Slip Line Theory
During indentation it is often important to determine the relationship between the average pressure and the yield strength. This work uses slip line theory to determine this relationship for the case of a rigid sphere indenting a frictionless perfectly plastic half-space (i.e. no hardening). The results show that the ratio between the average contact pressure and the yield strength decreases as the depth of indentation is increased. Note that the slip-line analysis does not include the effects of pile-up or sink-in deformations. However, the slip-line theory has also been compared to data generated using the finite element method (FEM). The theory and the FEM results appear to agree well.
2015-11-16T00:00:00ZTrust region methods for estimation of a complex exponential decay model in MRI with a single-shot or multi-shot trajectory (in review)http://hdl.handle.net/11200/485062015-05-05T13:18:19Z2015-05-05T00:00:00ZTrust region methods for estimation of a complex exponential decay model in MRI with a single-shot or multi-shot trajectory (in review)
Joint estimation of spin density, R2* decay and off-resonance frequency maps is very useful in many magnetic resonance imaging (MRI) applications. The standard multi-echo approach can achieve high accuracy but requires a long acquisition time for sampling multiple k-space frames. There are many approaches to accelerate the acquisition. Among them, single- or multi-shot trajectory based sampling has recently drawn attention due to its fast data acquisition. However, this sampling strategy destroys the Fourier relationship between k-space and images, leading to a great challenge for the reconstruction. In this work, we present two trust region methods based on two different linearization strategies for the nonlinear signal model. A trust region is defined as a local area in the variable space where a local linear approximation is trustable. In each iteration, the method minimizes a local approximation within a trust region so that the step size can be kept in a suitable scale. A continuation scheme is applied to gradually reduce the regularization over the parameter maps and facilitate convergence from poor initializations. The two trust region methods are compared to two other previously proposed methods---the nonlinear conjugate gradients and the gradual refinement algorithm. Experiments based on various synthetic data and real phantom data show that the two trust region methods have a clear advantage in both speed and stability.
2015-05-05T00:00:00ZAn efficient auxiliary variable method for quantification of spin density, R2* decay and field inhomogeneity maps in magnetic resonance imaginghttp://hdl.handle.net/11200/485052015-04-07T21:02:03Z2015-04-07T00:00:00ZAn efficient auxiliary variable method for quantification of spin density, R2* decay and field inhomogeneity maps in magnetic resonance imaging
Quantification of spin density, $R_2^*$ decay and off-resonance frequency maps is very important in some applications of magnetic resonance imaging (MRI). To reconstruct these parameter maps, a time-varying model such as mono-exponentials must be used to represent the signal from each voxel. When only a single-shot trajectory is adopted, the underlying reconstruction problem is significantly nonlinear and therefore requires an iterative algorithm. The regularized trust region method previously proposed to address this problem is stable but lacks speed. In this paper, we propose a novel auxiliary variable method that is very efficient in solving the underlying optimization problem. This method introduces an auxiliary variable in the spatial-temporal domain that separates the data fidelity term and the structure fidelity term. The algorithm then alternately optimizes the data fidelity and the structure fidelity to reach the solution. The data fidelity optimization has a closed-form solution and can be solved very efficiently. The structure fidelity optimization fits the exponential model with the auxiliary variable and can also be rapidly computed. Some preliminary comparisons between the auxiliary variable method and the trust region method show that the new method is 10 times faster than the trust region method at a reasonable reconstruction precision.
2015-04-07T00:00:00Z